The effect of vitamin D3 and 1,25-dihydroxyvitamin D3 on the toxic symptoms of cadmium exposed rats

The uptake and bioaccumulation of heavy metals by food plants, their effects on plants nutrients, and associated health risk: a review

Heavy metal contamination is a globally recognized environmental issue, threatening human life very seriously. Increasing population and high demand for food resulted in release of various contaminants into environment that finally contaminate the food chain. Edible plants are the major source of diet, and their contamination with toxic metals may result in catastrophic health hazards. Heavy metals affect the human health directly and/or indirectly; one of the indirect effects is the change in plant nutritional values. Previously, a number of review papers have been published on different aspects of heavy metal contamination. However, no related information is available about the effects of heavy metals on the nutritional status of food plants. This review paper is focused upon heavy metal sources, accumulation, transfer, health risk, and effects on protein, amino acids, carbohydrates, fats, and vitamins in plants. The literature about heavy metals in food plants shows that both leafy and nonleafy vegetables are good accumulators of heavy metals. In nonleafy vegetables, the bioaccumulation pattern was leaf > root ≈ stem > tuber. Heavy metals have strong influence on nutritional values; therefore, plants grown on metal-contaminated soil were nutrient deficient and consumption of such vegetables may lead to nutritional deficiency in the population particularly living in developing countries which are already facing the malnutrition problems.

The effects of cadmium in feed, and its amelioration with zinc, on element balances in sheep1

The effects of feeding Cd to sheep at a level that is typical of polluted regions were investigated, as well as possible amelioration by adding Zn to the diet. Welsh Mountain ewes (n = 24) were fed herb-age and concentrate in metabolism crates, with four supplement treatments in a two-factor factorial design: no supplement, Cd supplement only, Zn supplement only, and a combination of both the Cd and Zn supplement. Cadmium (286 microg/kg of feed DMI) and Zn (8.6 mg/kg feed DMI) were added as sulfates. Food and water intakes and element balances were recorded over 20 d after 7 d dietary adaptation, and element concentrations were determined in wool samples. Neither metal affected DMI or digestibility (P > 0.15), but water intake (P = 0.001) and urine output (P = 0.03) were decreased when only the Zn supplement was added. Water retention was increased by the Cd supplement (P = 0.04). In wool, the Cd supplement greatly increased the K concentration if no Zn supplement was fed (P = 0.02), and the Zn supplement decreased Mn concentration (P = 0.02). Cadmium in feed increased the Cd balance and produced several mineral disturbances, in particular a decrease in Na balance that is typical of renal tubular disorders. Adding Zn as well as Cd to feed returned the Cd balance to a level similar to that of sheep receiving neither Cd nor Zn, which suggests that Zn status is critical in determining whether Cd in feed increases the Cd balance in sheep. Feeding Cd also increased urinary K, Fe, Mo, Cr, B, and Ca concentrations, even when supplementary Zn was fed. It is concluded that low levels of Cd in sheep feed can increase the Cd balance if adequate Zn is not provided, which can lead to subclinical mineral disturbances and changes in the mineral concentrations in wool.

Behavioural and biochemical changes after simultaneous and post-treatment of vitamin A and D on cadmium toxicity

In the present study, an investigation was undertaken to assess the protective efficacy in cadmium toxicity of vitamins administered simultaneously as well as post-treatment. Rats were treated with cadmium 1 mg/kg body weight (bw) powdered vitamin A chewable tablet 500 IU/kg bw/day and injectable vitamin D(3) (made into a suspension with gum tragacanth in 100 ml distilled water) 100 IU/kg bw/day, mixed with powdered pellet feed and fed to experimental animals. Spontaneous motor activity and Rota Rod Endurance time was recorded after both simultaneous (for 21 days) and post-treatment (42 days). Vitamin treated animals by themselves behaved like controls but attenuated the cadmium effect when given Cd simultaneously or as post-treatment. While the biochemical changes were assayed, vitamins which did not have any influence on their own, given simultaneously and as post-treatment, antagonized the cadmium effect on heart, liver tissues and serum. Both simultaneous and post-cadmium and -vitamin treatments significantly increased the activities of the enzymes aspartic amino transferase, alanine aminotransferase, acid phosphatase and alkaline phosphatase in tissues and serum. Simultaneous and post-vitamin treatment with Cd had an effect of bringing back the activity of the enzymes closer to control values. These data suggest that treatment with vitamin A and D can minimise the Cd effect when given to the population exposed to Cd.